Effect of sieve plate packing on bubble size distribution in a cyclonic flotation column

Abstract

The application of packed technology effectively reduces the height of flotation column and improves the treatment capacity. The effect of packed sieve plate on bubble size and velocity in flotation column affect the flotation recovery. Based on high-speed dynamic measurement and particle image velocimetry (PIV) measurement, the velocity and size of bubbles in open and packed flotation column were compared first and then the effect of different packing method was studied. With sieve plate packing, the peak tangential velocity of bubble decreased by 92%; the number of bubbles within the range of 1–2.5 mm increased from 62.79% to 83.34% and the mean bubble diameter decrease from 2.14 mm to 1.82 mm. Sieve plate packed weakens the influence of rotation flow, reduces the bubble size and makes the distribution is more uniform in flotation column, which is conducive to the collision and adhesion of particles and bubbles. The effect study of opening hole size, thickness and packed position of sieve plate on bubble size distribution shows that the small opening hole size of sieve plate has a strong segmentation effect on bubbles, and can reduce the bubble size; Thick sieve plate will increase bubble coalescence and increase bubble size; The bubbles have a good distribution with sieve plate packed at a height of 0.5 times the diameter of the column. This study can provide guidance for the design of packed method in flotation column.